Tamerlan Tsarnaev, a 26-year-old who had been known to the FBI as Suspect No. 1 and was seen in surveillance footage in a black baseball cap, was killed overnight, officials said.

His brother, a 19-year-old college student who was dubbed Suspect No. 2, escaped. He was seen wearing a white, backward baseball cap in the images from Monday's deadly bombing at the marathon finish line.

"Dzhokhar, if you are alive, turn yourself in and ask for forgiveness from the victims, from the injured and from those who left," Tsarni said, raising his voice.

The brothers lived near Boston and had been in the U.S. for about a decade, though Tsarni said he had not seen them since December 2005. He said his nephews had struggled to settle themselves in the U.S. and ended up "thereby just hating everyone."

Asked what he thought provoked the bombings, Tsarni said: "Being losers, hatred to those who were able to settle themselves. These are the only reasons I can imagine of. Anything else, anything else to do with religion, with Islam, it's a fraud, it's a fake."

Pressed again toward the end of the impromptu interview, he said he was not calling his nephews losers. "I'm saying those who are able to make this atrocity are only losers."

Chechnya has been plagued by an Islamic insurgency that has carried out deadly bombings. Tsarni, who described himself as Muslim, vehemently denied that Chechnya or Islam had anything to do with the attack.

Tsarni said his brother left the U.S. and he had not talked to him since 2009. He said they had a personal falling out but did not elaborate.

"If somebody radicalized them ... it's not my brother, who just moved back to Russia. Who spent his life bringing bread to that table, fixing cars."

He offered his condolences to the victims.

"We're sharing with them their grief. I'm ready just to meet with them. I'm ready just to bend in front of them, to kneel in front of them, seeking that forgiveness."